Although various antioxidants have long been known to be effective stabilizers for polymeric resins and have enjoyed wide commercial success for that use, these same stabilized polymeric resin compositions continue to discolor upon heating at elevated temperatures for prolonged periods or upon exposure to the combustion products of natural gas.
While the addition of organic phosphites to such resin compositions stabilized with phenolic antioxidants tends to reduce the discoloration, it remains a serious practical problem.
Likewise polymeric resin compositions containing certain phenolic antioxidants and hindered amine stabilizers tend to discolor upon storage for extended periods even at ambient temperatures.
The organic hydroxylamine compounds, such as those found in U.S. Pat. Nos. 3,644,278 and 3,778,464, have also been used as antioxidant stabilizers for hydrocarbons including polyolefins. The use of the hydroxylamines in polyolefins in combination with a phenolic antioxidant or in combination with an organic phosphorus compound, an ultraviolet light absorber, a thiosynergist, or a hindered amine stabilizer with the resulting resistance to degradation and/or discoloration is disclosed in U.S. Pat. No. 4,590,231. Although such stabilized polyolefin compositions are improved, there continues to exist a need and desire to provide polymeric resin compositions which exhibit enhanced levels of stability and to provide alternate stabilizer compositions for incorporation into polymer compositions.
The tertiary amine oxides are widely used commercially as organic surfactants. Such surfactants have properties that make them very useful in shampoos, hair conditioners, dish and laundry detergents, fabric softeners and the like. The use of tertiary amine oxides until this time as stabilizer additives for polymeric resins, however, is believe to be novel, especially when used in combination with other additives.